Ransomware is a type of malware that blocks access to your files and systems until you pay a ransom. The first example of ransomware happened on September 5, 2013, when Cryptolocker was unleashed. It quickly affected many systems with hackers requiring users to pay money for the decryption keys.

According to a February 2015 McAfee Labs Threats Report, the number of ransomware types grows an average of 155 percent each quarter.